Soil Nutrient Monitored Village in Jianghuai and Huaibei Districts, Anhui

The Jianghui soil nutrient monitoring village was established to represent soil types and agricultural production conditions in yellow-drab soils of the northern sub-tropical zone. The village has 2,180 people and 263 hectares (ha) of cultivated land (161 ha in paddy fields). Soil samples (373) were collected (100 m² grid) and will be analysed to determine nutrient content and variability.

In the Huaibei monitored village, 93 percent of 178 soil samples were below the critical level [78 parts per million (ppm)] in available soil potassium (K), 54 percent had soil K levels below 50 ppm (seriously K deficient), 73 percent were phoshorus (P) deficient (lower than 12 ppm), 99 percent were zinc (Zn) deficient (lower than 2 ppm), and 71 percent were manganese (Mn) deficient (lower than 5 ppm).

A survey found that most farmers apply urea and diammonium phosphate (DAP) or ammonium bicarbonate (ABC) and single super phosphate (SSP) for winter wheat. A portion of farmers apply 300 to 450 kg N-P₂O₅-K₂O/ha using blended fertilizer, and a few apply potassium chloride (KCl) at rates ranging between 68 to 90 kg K₂O/ha. In autumn, only urea or ABC was applied for maize and sweet potato. Calculations reveal nutrient imbalances for N and P and a serious imbalance for K.

Potassium fertilizer efficiently promoted growth of wheat and maize, increased the output value, and raised farmer income. Wheat and maize yields without K were 3,740 kg/ha and 7,890 kg/ha, respectively. With K, average yields increased by 18 and 8 percent over the zero K treatments, respectively. Compared to the check, K increased net income from wheat by US$43 to US$59/ha. Potassium increased net income from maize by US$21 to US$79/ha over the control. The value to cost ratio for K in both wheat and maize ranged between 1.7 to 3.2. Annual field trials found a need for K in wheat and maize crops, and the optimum K rate was determined to be near 120 kg K₂O/ha. Phosphorus fertilizer did not show significant effects in wheat and maize, but the optimum P fertilizer application rate is considered to be between 60 to 90 kg P₂O₅/ha. ANHUI-NMS12